Title explains most of it. I was asked if plugging BOTH the molex and SATA power cables into a SATA HDD with both types of connections would do any harm, I said plugging both in would likely cause enough of a zap to destroy the data on the HDD, if not kill the HDD due to too much voltage being fed to it. Somebody I don't even know then butted in saying nothing would happen, an I was like voltage dude, voltage! So to try and settle this once and for all, does anyone have a SATA HDD with both SATA and molex power connections or knowns in general what may happen. The HDD in question is a Western Digital.

I have plugged both in by accident and nothing happened with the WD cavier 160GB SATA.
I was certain I was plugging in the power to my IDE but I didn't notice the SATA power connector right next to it for some reason.

Title explains most of it. I was asked if plugging BOTH the molex and SATA power cables into a SATA HDD with both types of connections would do any harm, I said plugging both in would likely cause enough of a zap to destroy the data on the HDD, if not kill the HDD due to too much voltage being fed to it. Somebody I don't even know then butted in saying nothing would happen, an I was like voltage dude, voltage! So to try and settle this once and for all, does anyone have a SATA HDD with both SATA and molex power connections or knowns in general what may happen. The HDD in question is a Western Digital.

Click to expand...

Yeah, don't connect both, it is BAD! I have 3 WD drives with both, and it is clearly marked not to do it.

Title explains most of it. I was asked if plugging BOTH the molex and SATA power cables into a SATA HDD with both types of connections would do any harm, I said plugging both in would likely cause enough of a zap to destroy the data on the HDD, if not kill the HDD due to too much voltage being fed to it. Somebody I don't even know then butted in saying nothing would happen, an I was like voltage dude, voltage! So to try and settle this once and for all, does anyone have a SATA HDD with both SATA and molex power connections or knowns in general what may happen. The HDD in question is a Western Digital.

Click to expand...

they die. WD are the only ones with both connectors, and they will either not power on until you remove one, or they will just die and never power on again. if you buy them retail (in a box, not OEM) they often have a warning sticker/pamphlet with them.

they die. WD are the only ones with both connectors, and they will either not power on until you remove one, or they will just die and never power on again. if you buy them retail (in a box, not OEM) they often have a warning sticker/pamphlet with them.

i cant think of any reason connecting both at the same time would hurt the drive or power supply. all you are doing is connecting two wires with the same voltage to one device so its not like they are different voltages.

(im not that sure about power supply to sata drives so forgive me if im wrong about not using different voltages)

i think the reason you are told not to connect both at the same time is in the event of a short circuit it may not have proper trip protection to your system.

naturally you dont want to be doing it if you run dual psu. (might mix up the wires)

As for voltage, logically you'd think the wires end up together anyway and therefor the voltage would remain the same as it is connected parallel. For some reason it doesn't work this way and drives can die when both connectors are connected. As mentioned above some drives simply don't work, they're probably protected against this kind of misuse.

As for voltage, logically you'd think the wires end up together anyway and therefor the voltage would remain the same as it is connected parallel. For some reason it doesn't work this way and drives can die when both connectors are connected. As mentioned above some drives simply don't work, they're probably protected against this kind of misuse.

Click to expand...

it must be like ac fans then, they have speeds regulated by sending power through more or less windings which increases or decreases speeds but if two are connected to power at the same time they cause a backfeed of electricity that shorts out the whole motor even thou nothing was actually grounded.

As for voltage, logically you'd think the wires end up together anyway and therefor the voltage would remain the same as it is connected parallel. For some reason it doesn't work this way and drives can die when both connectors are connected. As mentioned above some drives simply don't work, they're probably protected against this kind of misuse.

Click to expand...

its because of voltage differences, one could be 5.05v and the other 4.95v, and if so the power can try and travel backwards along some paths to 'even' the voltages out. This obviously doesnt go well, and the drive could shut off for safety, or have the electrics just die.

Ok here's an extension of your question. I have 2 WD Raptors, each with the SATA power plugged into the PSU, but with an HDD cooler fan/heatsink plugged into its MOLEX connector leeching power that way. The fans work, and so do the HDDs, perfectly actually.
Now, I just setup my PC within the past week, so I'm wondering about long-term? Is it alright to be leeching power this way?

Ok here's an extension of your question. I have 2 WD Raptors, each with the SATA power plugged into the PSU, but with an HDD cooler fan/heatsink plugged into its MOLEX connector leeching power that way. The fans work, and so do the HDDs, perfectly actually.
Now, I just setup my PC within the past week, so I'm wondering about long-term? Is it alright to be leeching power this way?

Click to expand...

Woah woah what?

Let me get this straight. You have your HDD plugged in via SATA, and the Heatsink/fan is plugged into the molex ON the HDD itself?

I'm surprised it works. NO, that's REALLY not a good idea. It needs to be plugged into a seperate molex.

Nonsense, it's logical that it works, the wires are connected directly and there is no reason it should be bad.

Click to expand...

From what I read it wasn't. He had the HDD plugged in by the SATA power cable, and the fan/heatsink plugged into the molex of the HDD. That would mean the HDD is acting as a bypass, which can't be good for it.

Does WD even make hdds with the dual power connector config any more? I had one that went bad (NOT because of connecting both in, for an unrelated reason), and the replacemnt didnt have the molex connector, just sata pwr. Same model number and everything, differnt revision though.